html, body {
      height: 100%;
      min-height: 100%;
      margin: 0;
      padding: 0;
    }
    body {
      min-height: 100vh;
      height: 100vh;
      display: flex;
      flex-direction: column;
      background: linear-gradient(135deg, #000 0%, #DD0000 50%, #FFCC00 100%);
      background-attachment: fixed;
      box-sizing: border-box;
    }
    ul {
      list-style-type: none;
    }
    header {
      width: 100%;
      background: rgba(0,0,0,0.8);
      box-shadow: 0 2px 16px rgba(0,0,0,0.15);
      display: flex;
      flex-direction: column;
      align-items: center;
      justify-content: center;
      padding-top: 1rem;
      padding-bottom: 0.5rem;
    }
    .nav-buttons {
      display: flex;
      flex-direction: row;
      justify-content: center;
      align-items: center;
      gap: 1rem;
    }
    .btn-nav {
      background: #000;
      color: #FFCC00;
      font-weight: 700;
      padding: 0.5rem 2rem;
      border-radius: 0.375rem;
      border: 2px solid #DD0000;
      transition: background 0.3s, color 0.3s, border 0.3s;
      user-select: none;
    }
    .btn-nav:hover:not(:disabled) {
      background: #DD0000;
      color: #000;
      border-color: #FFCC00;
      cursor: pointer;
    }
    .btn-nav:disabled {
      opacity: 0.5;
      cursor: not-allowed;
    }
    main {
      flex: 1 1 0;
      display: flex;
      align-items: center;
      justify-content: center;
      width: 100vw;
      min-height: 0;
      min-width: 0;
    }
    .slide {
      width: 100%;
      max-width: 600px;
      margin: auto;
      padding: 2rem 1rem;
      border-radius: 1rem;
      background: rgba(0,0,0,0.5);
      box-shadow: 0 4px 32px rgba(0,0,0,0.2);
      color: #fff;
      text-align: center;
      opacity: 0;
      pointer-events: none;
      position: absolute;
      left: 0;
      right: 0;
      transition: opacity 0.5s;
    }
    .slide.active {
      opacity: 1;
      pointer-events: auto;
      position: relative;
    }
    /* Two-image layout */
    .slide-images {
      display: flex;
      justify-content: center;
      align-items: center;
      gap: 2rem;
      margin-bottom: 1.5rem;
    }
    .slide-images img {
      width: 80px;
      height: 80px;
      border-radius: 0.6rem;
      box-shadow: 0 2px 12px rgba(0,0,0,0.15);
      background: transparent;
    }
    @media (max-width: 700px) {
      .slide {
        max-width: 95vw;
        padding: 1rem 0.5rem;
      }
      h2 {
        font-size: 2rem !important;
      }

      .slide-images img {
        max-width: 90%;
      }
    }